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path: root/src/backend/libpq/auth.c
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2024-01-03Avoid masking EOF (no-password-supplied) conditions in auth.c.Tom Lane
CheckPWChallengeAuth() would return STATUS_ERROR if the user does not exist or has no password assigned, even if the client disconnected without responding to the password challenge (as libpq often will, for example). We should return STATUS_EOF in that case, and the lower-level functions do, but this code level got it wrong since the refactoring done in 7ac955b34. This breaks the intent of not logging anything for EOF cases (cf. comments in auth_failed()) and might also confuse users of ClientAuthentication_hook. Per report from Liu Lang. Back-patch to all supported versions. Discussion: https://postgr.es/m/b725238c-539d-cb09-2bff-b5e6cb2c069c@esgyn.cn
2021-06-23Don't assume GSSAPI result strings are null-terminated.Tom Lane
Our uses of gss_display_status() and gss_display_name() assumed that the gss_buffer_desc strings returned by those functions are null-terminated. It appears that they generally are, given the lack of field complaints up to now. However, the available documentation does not promise this, and some man pages for gss_display_status() show examples that rely on the gss_buffer_desc.length field instead of expecting null termination. Also, we now have a report that on some implementations, clang's address sanitizer is of the opinion that the byte after the specified length is undefined. Hence, change the code to rely on the length field instead. This might well be cosmetic rather than fixing any real bug, but it's hard to be sure, so back-patch to all supported branches. While here, also back-patch the v12 changes that made pg_GSS_error deal honestly with multiple messages available from gss_display_status. Per report from Sudheer H R. Discussion: https://postgr.es/m/5372B6D4-8276-42C0-B8FB-BD0918826FC3@tekenlight.com
2020-12-30Fix up usage of krb_server_keyfile GUC parameter.Tom Lane
secure_open_gssapi() installed the krb_server_keyfile setting as KRB5_KTNAME unconditionally, so long as it's not empty. However, pg_GSS_recvauth() only installed it if KRB5_KTNAME wasn't set already, leading to a troubling inconsistency: in theory, clients could see different sets of server principal names depending on whether they use GSSAPI encryption. Always using krb_server_keyfile seems like the right thing, so make both places do that. Also fix up secure_open_gssapi()'s lack of a check for setenv() failure --- it's unlikely, surely, but security-critical actions are no place to be sloppy. Also improve the associated documentation. This patch does nothing about secure_open_gssapi()'s use of setenv(), and indeed causes pg_GSS_recvauth() to use it too. That's nominally against project portability rules, but since this code is only built with --with-gssapi, I do not feel a need to do something about this in the back branches. A fix will be forthcoming for HEAD though. Back-patch to v12 where GSSAPI encryption was introduced. The dubious behavior in pg_GSS_recvauth() goes back further, but it didn't have anything to be inconsistent with, so let it be. Discussion: https://postgr.es/m/2187460.1609263156@sss.pgh.pa.us
2020-12-28Improve log messages related to pg_hba.conf not matching a connection.Tom Lane
Include details on whether GSS encryption has been activated; since we added "hostgssenc" type HBA entries, that's relevant info. Kyotaro Horiguchi and Tom Lane. Back-patch to v12 where GSS encryption was introduced. Discussion: https://postgr.es/m/e5b0b6ed05764324a2f3fe7acfc766d5@smhi.se
2020-12-28Fix assorted issues in backend's GSSAPI encryption support.Tom Lane
Unrecoverable errors detected by GSSAPI encryption can't just be reported with elog(ERROR) or elog(FATAL), because attempting to send the error report to the client is likely to lead to infinite recursion or loss of protocol sync. Instead make this code do what the SSL encryption code has long done, which is to just report any such failure to the server log (with elevel COMMERROR), then pretend we've lost the connection by returning errno = ECONNRESET. Along the way, fix confusion about whether message translation is done by pg_GSS_error() or its callers (the latter should do it), and make the backend version of that function work more like the frontend version. Avoid allocating the port->gss struct until it's needed; we surely don't need to allocate it in the postmaster. Improve logging of "connection authorized" messages with GSS enabled. (As part of this, I back-patched the code changes from dc11f31a1.) Make BackendStatusShmemSize() account for the GSS-related space that will be allocated by CreateSharedBackendStatus(). This omission could possibly cause out-of-shared-memory problems with very high max_connections settings. Remove arbitrary, pointless restriction that only GSS authentication can be used on a GSS-encrypted connection. Improve documentation; notably, document the fact that libpq now prefers GSS encryption over SSL encryption if both are possible. Per report from Mikael Gustavsson. Back-patch to v12 where this code was introduced. Discussion: https://postgr.es/m/e5b0b6ed05764324a2f3fe7acfc766d5@smhi.se
2019-11-05Avoid logging complaints about abandoned connections when using PAM.Tom Lane
For a long time (since commit aed378e8d) we have had a policy to log nothing about a connection if the client disconnects when challenged for a password. This is because libpq-using clients will typically do that, and then come back for a new connection attempt once they've collected a password from their user, so that logging the abandoned connection attempt will just result in log spam. However, this did not work well for PAM authentication: the bottom-level function pam_passwd_conv_proc() was on board with it, but we logged messages at higher levels anyway, for lack of any reporting mechanism. Add a flag and tweak the logic so that the case is silent, as it is for other password-using auth mechanisms. Per complaint from Yoann La Cancellera. It's been like this for awhile, so back-patch to all supported branches. Discussion: https://postgr.es/m/CACP=ajbrFFYUrLyJBLV8=q+eNCapa1xDEyvXhMoYrNphs-xqPw@mail.gmail.com
2019-09-23Message style fixesPeter Eisentraut
2019-07-31Remove superfluous newlines in function prototypes.Andres Freund
These were introduced by pgindent due to fixe to broken indentation (c.f. 8255c7a5eeba8). Previously the mis-indentation of function prototypes was creatively used to reduce indentation in a few places. As that formatting only exists in master and REL_12_STABLE, it seems better to fix it in both, rather than having some odd indentation in v12 that somebody might copy for future patches or such. Author: Andres Freund Discussion: https://postgr.es/m/20190728013754.jwcbe5nfyt3533vx@alap3.anarazel.de Backpatch: 12-
2019-06-08Move be-gssapi-common.h into src/include/libpq/Michael Paquier
The file has been introduced in src/backend/libpq/ as of b0b39f72, but all backend-side headers of libpq are located in src/include/libpq/. Note that the identification path on top of the file referred to src/include/libpq/ from the start. Author: Michael Paquier Reviewed-by: Stephen Frost Discussion: https://postgr.es/m/20190607043415.GE1736@paquier.xyz
2019-05-22Phase 2 pgindent run for v12.Tom Lane
Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22Initial pgindent run for v12.Tom Lane
This is still using the 2.0 version of pg_bsd_indent. I thought it would be good to commit this separately, so as to document the differences between 2.0 and 2.1 behavior. Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
2019-04-03GSSAPI encryption supportStephen Frost
On both the frontend and backend, prepare for GSSAPI encryption support by moving common code for error handling into a separate file. Fix a TODO for handling multiple status messages in the process. Eliminate the OIDs, which have not been needed for some time. Add frontend and backend encryption support functions. Keep the context initiation for authentication-only separate on both the frontend and backend in order to avoid concerns about changing the requested flags to include encryption support. In postmaster, pull GSSAPI authorization checking into a shared function. Also share the initiator name between the encryption and non-encryption codepaths. For HBA, add "hostgssenc" and "hostnogssenc" entries that behave similarly to their SSL counterparts. "hostgssenc" requires either "gss", "trust", or "reject" for its authentication. Similarly, add a "gssencmode" parameter to libpq. Supported values are "disable", "require", and "prefer". Notably, negotiation will only be attempted if credentials can be acquired. Move credential acquisition into its own function to support this behavior. Add a simple pg_stat_gssapi view similar to pg_stat_ssl, for monitoring if GSSAPI authentication was used, what principal was used, and if encryption is being used on the connection. Finally, add documentation for everything new, and update existing documentation on connection security. Thanks to Michael Paquier for the Windows fixes. Author: Robbie Harwood, with changes to the read/write functions by me. Reviewed in various forms and at different times by: Michael Paquier, Andres Freund, David Steele. Discussion: https://www.postgresql.org/message-id/flat/jlg1tgq1ktm.fsf@thriss.redhat.com
2019-03-21Add DNS SRV support for LDAP server discovery.Thomas Munro
LDAP servers can be advertised on a network with RFC 2782 DNS SRV records. The OpenLDAP command-line tools automatically try to find servers that way, if no server name is provided by the user. Teach PostgreSQL to do the same using OpenLDAP's support functions, when building with OpenLDAP. For now, we assume that HAVE_LDAP_INITIALIZE (an OpenLDAP extension available since OpenLDAP 2.0 and also present in Apple LDAP) implies that you also have ldap_domain2hostlist() (which arrived in the same OpenLDAP version and is also present in Apple LDAP). Author: Thomas Munro Reviewed-by: Daniel Gustafsson Discussion: https://postgr.es/m/CAEepm=2hAnSfhdsd6vXsM6VZVN0br-FbAZ-O+Swk18S5HkCP=A@mail.gmail.com
2019-03-09Add new clientcert hba option verify-fullMagnus Hagander
This allows a login to require both that the cn of the certificate matches (like authentication type cert) *and* that another authentication method (such as password or kerberos) succeeds as well. The old value of clientcert=1 maps to the new clientcert=verify-ca, clientcert=0 maps to the new clientcert=no-verify, and the new option erify-full will add the validation of the CN. Author: Julian Markwort, Marius Timmer Reviewed by: Magnus Hagander, Thomas Munro
2019-02-14Get rid of another unconstify through API changesPeter Eisentraut
This also makes the code in read_client_first_message() more similar to read_client_final_message(). Reported-by: Mark Dilger <hornschnorter@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/53a28052-f9f3-1808-fed9-460fd43035ab%402ndquadrant.com
2019-02-13More unconstify usePeter Eisentraut
Replace casts whose only purpose is to cast away const with the unconstify() macro. Discussion: https://www.postgresql.org/message-id/flat/53a28052-f9f3-1808-fed9-460fd43035ab%402ndquadrant.com
2019-01-02Update copyright for 2019Bruce Momjian
Backpatch-through: certain files through 9.4
2019-01-01Remove configure switch --disable-strong-randomMichael Paquier
This removes a portion of infrastructure introduced by fe0a0b5 to allow compilation of Postgres in environments where no strong random source is available, meaning that there is no linking to OpenSSL and no /dev/urandom (Windows having its own CryptoAPI). No systems shipped this century lack /dev/urandom, and the buildfarm is actually not testing this switch at all, so just remove it. This simplifies particularly some backend code which included a fallback implementation using shared memory, and removes a set of alternate regression output files from pgcrypto. Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/20181230063219.GG608@paquier.xyz
2018-11-28Don't set PAM_RHOST for Unix sockets.Thomas Munro
Since commit 2f1d2b7a we have set PAM_RHOST to "[local]" for Unix sockets. This caused Linux PAM's libaudit integration to make DNS requests for that name. It's not exactly clear what value PAM_RHOST should have in that case, but it seems clear that we shouldn't set it to an unresolvable name, so don't do that. Back-patch to 9.6. Bug #15520. Author: Thomas Munro Reviewed-by: Peter Eisentraut Reported-by: Albert Schabhuetl Discussion: https://postgr.es/m/15520-4c266f986998e1c5%40postgresql.org
2018-11-13Fix const correctness warning.Thomas Munro
Per buildfarm.
2018-11-13Fix handling of HBA ldapserver with multiple hostnames.Thomas Munro
Commit 35c0754f failed to handle space-separated lists of alternative hostnames in ldapserver, when building a URI for ldap_initialize() (OpenLDAP). Such lists need to be expanded to space-separated URIs. Repair. Back-patch to 11, to fix bug report #15495. Author: Thomas Munro Reported-by: Renaud Navarro Discussion: https://postgr.es/m/15495-2c39fc196c95cd72%40postgresql.org
2018-08-24Suppress uninitialized-variable warning in new SCRAM code.Tom Lane
While we generally don't sweat too much about "may be used uninitialized" warnings from older compilers, I noticed that there's a fair number of buildfarm animals that are producing such a warning *only* for this variable. So it seems worth silencing.
2018-08-21Fix set of NLS translation issuesMichael Paquier
While monitoring the code, a couple of issues related to string translation has showed up: - Some routines for auto-updatable views return an error string, which sometimes missed the shot. A comment regarding string translation is added for each routine to help with future features. - GSSAPI authentication missed two translations. - vacuumdb handles non-translated strings. - GetConfigOptionByNum should translate strings. This part is not back-patched as after a minor upgrade this could be surprising for users. Reported-by: Kyotaro Horiguchi Author: Kyotaro Horiguchi Reviewed-by: Michael Paquier, Tom Lane Discussion: https://postgr.es/m/20180810.152131.31921918.horiguchi.kyotaro@lab.ntt.co.jp Backpatch-through: 9.3
2018-08-05Remove support for tls-unique channel binding.Heikki Linnakangas
There are some problems with the tls-unique channel binding type. It's not supported by all SSL libraries, and strictly speaking it's not defined for TLS 1.3 at all, even though at least in OpenSSL, the functions used for it still seem to work with TLS 1.3 connections. And since we had no mechanism to negotiate what channel binding type to use, there would be awkward interoperability issues if a server only supported some channel binding types. tls-server-end-point seems feasible to support with any SSL library, so let's just stick to that. This removes the scram_channel_binding libpq option altogether, since there is now only one supported channel binding type. This also removes all the channel binding tests from the SSL test suite. They were really just testing the scram_channel_binding option, which is now gone. Channel binding is used if both client and server support it, so it is used in the existing tests. It would be good to have some tests specifically for channel binding, to make sure it really is used, and the different combinations of a client and a server that support or doesn't support it. The current set of settings we have make it hard to write such tests, but I did test those things manually, by disabling HAVE_BE_TLS_GET_CERTIFICATE_HASH and/or HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH. I also removed the SCRAM_CHANNEL_BINDING_TLS_END_POINT constant. This is a matter of taste, but IMO it's more readable to just use the "tls-server-end-point" string. Refactor the checks on whether the SSL library supports the functions needed for tls-server-end-point channel binding. Now the server won't advertise, and the client won't choose, the SCRAM-SHA-256-PLUS variant, if compiled with an OpenSSL version too old to support it. In the passing, add some sanity checks to check that the chosen SASL mechanism, SCRAM-SHA-256 or SCRAM-SHA-256-PLUS, matches whether the SCRAM exchange used channel binding or not. For example, if the client selects the non-channel-binding variant SCRAM-SHA-256, but in the SCRAM message uses channel binding anyway. It's harmless from a security point of view, I believe, and I'm not sure if there are some other conditions that would cause the connection to fail, but it seems better to be strict about these things and check explicitly. Discussion: https://www.postgresql.org/message-id/ec787074-2305-c6f4-86aa-6902f98485a4%40iki.fi
2018-05-21Fix unsafe usage of strerror(errno) within ereport().Tom Lane
This is the converse of the unsafe-usage-of-%m problem: the reason ereport/elog provide that format code is mainly to dodge the hazard of errno getting changed before control reaches functions within the arguments of the macro. I only found one instance of this hazard, but it's been there since 9.4 :-(.
2018-01-30Fix up references to scram-sha-256Peter Eisentraut
pg_hba_file_rules erroneously reported this as scram-sha256. Fix that. To avoid future errors and confusion, also adjust documentation links and internal symbols to have a separator between "sha" and "256". Reported-by: Christophe Courtois <christophe.courtois@dalibo.com> Author: Michael Paquier <michael.paquier@gmail.com>
2018-01-04Refactor channel binding code to fetch cbind_data only when necessaryPeter Eisentraut
As things stand now, channel binding data is fetched from OpenSSL and saved into the SCRAM exchange context for any SSL connection attempted for a SCRAM authentication, resulting in data fetched but not used if no channel binding is used or if a different channel binding type is used than what the data is here for. Refactor the code in such a way that binding data is fetched from the SSL stack only when a specific channel binding is used for both the frontend and the backend. In order to achieve that, save the libpq connection context directly in the SCRAM exchange state, and add a dependency to SSL in the low-level SCRAM routines. This makes the interface in charge of initializing the SCRAM context cleaner as all its data comes from either PGconn* (for frontend) or Port* (for the backend). Author: Michael Paquier <michael.paquier@gmail.com>
2018-01-04Define LDAPS_PORT if it's missing and disable implicit LDAPS on WindowsPeter Eisentraut
Some versions of Windows don't define LDAPS_PORT. Also, Windows' ldap_sslinit() is documented to use LDAPS even if you said secure=0 when the port number happens to be 636 or 3269. Let's avoid using the port number to imply that you want LDAPS, so that connection strings have the same meaning on Windows and Unix. Author: Thomas Munro Discussion: https://postgr.es/m/CAEepm%3D23B7GV4AUz3MYH1TKpTv030VHxD2Sn%2BLYWDv8d-qWxww%40mail.gmail.com
2018-01-03Allow ldaps when using ldap authenticationPeter Eisentraut
While ldaptls=1 provides an RFC 4513 conforming way to do LDAP authentication with TLS encryption, there was an earlier de facto standard way to do LDAP over SSL called LDAPS. Even though it's not enshrined in a standard, it's still widely used and sometimes required by organizations' network policies. There seems to be no reason not to support it when available in the client library. Therefore, add support when using OpenLDAP 2.4+ or Windows. It can be configured with ldapscheme=ldaps or ldapurl=ldaps://... Add tests for both ways of requesting LDAPS and a test for the pre-existing ldaptls=1. Modify the 001_auth.pl test for "diagnostic messages", which was previously relying on the server rejecting ldaptls=1. Author: Thomas Munro Reviewed-By: Peter Eisentraut Discussion: https://postgr.es/m/CAEepm=1s+pA-LZUjQ-9GQz0Z4rX_eK=DFXAF1nBQ+ROPimuOYQ@mail.gmail.com
2018-01-02Update copyright for 2018Bruce Momjian
Backpatch-through: certain files through 9.3
2017-12-18Move SCRAM-related name definitions to scram-common.hPeter Eisentraut
Mechanism names for SCRAM and channel binding names have been included in scram.h by the libpq frontend code, and this header references a set of routines which are only used by the backend. scram-common.h is on the contrary usable by both the backend and libpq, so getting those names from there seems more reasonable. Author: Michael Paquier <michael.paquier@gmail.com>
2017-11-29Update typedefs.list and re-run pgindentRobert Haas
Discussion: http://postgr.es/m/CA+TgmoaA9=1RWKtBWpDaj+sF3Stgc8sHgf5z=KGtbjwPLQVDMA@mail.gmail.com
2017-11-18Support channel binding 'tls-unique' in SCRAMPeter Eisentraut
This is the basic feature set using OpenSSL to support the feature. In order to allow the frontend and the backend to fetch the sent and expected TLS Finished messages, a PG-like API is added to be able to make the interface pluggable for other SSL implementations. This commit also adds a infrastructure to facilitate the addition of future channel binding types as well as libpq parameters to control the SASL mechanism names and channel binding names. Those will be added by upcoming commits. Some tests are added to the SSL test suite to test SCRAM authentication with channel binding. Author: Michael Paquier <michael@paquier.xyz> Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
2017-11-10Fix some null pointer dereferences in LDAP auth codePeter Eisentraut
An LDAP URL without a host name such as "ldap://" or without a base DN such as "ldap://localhost" would cause a crash when reading pg_hba.conf. If no binddn is configured, an error message might end up trying to print a null pointer, which could crash on some platforms. Author: Thomas Munro <thomas.munro@enterprisedb.com> Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-11-10Add some const decorations to prototypesPeter Eisentraut
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
2017-10-19Fix typoMagnus Hagander
Masahiko Sawada
2017-10-12Attempt to fix LDAP buildPeter Eisentraut
Apparently, an older spelling of LDAP_OPT_DIAGNOSTIC_MESSAGE is LDAP_OPT_ERROR_STRING, so fall back to that one.
2017-10-12Log diagnostic messages if errors occur during LDAP auth.Peter Eisentraut
Diagnostic messages seem likely to help users diagnose root causes more easily, so let's report them as errdetail. Author: Thomas Munro Reviewed-By: Ashutosh Bapat, Christoph Berg, Alvaro Herrera, Peter Eisentraut Discussion: https://postgr.es/m/CAEepm=2_dA-SYpFdmNVwvKsEBXOUj=K4ooKovHmvj6jnMdt8dw@mail.gmail.com
2017-10-12Improve LDAP cleanup code in error paths.Peter Eisentraut
After calling ldap_unbind_s() we probably shouldn't try to use the LDAP connection again to call ldap_get_option(), even if it failed. The OpenLDAP man page for ldap_unbind[_s] says "Once it is called, the connection to the LDAP server is closed, and the ld structure is invalid." Otherwise, as a general rule we should probably call ldap_unbind() before returning in all paths to avoid leaking resources. It is unlikely there is any practical leak problem since failure to authenticate currently results in the backend exiting soon afterwards. Author: Thomas Munro Reviewed-By: Alvaro Herrera, Peter Eisentraut Discussion: https://postgr.es/m/20170914141205.eup4kxzlkagtmfac%40alvherre.pgsql
2017-10-11Replace remaining uses of pq_sendint with pq_sendint{8,16,32}.Andres Freund
pq_sendint() remains, so extension code doesn't unnecessarily break. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
2017-10-01Replace most usages of ntoh[ls] and hton[sl] with pg_bswap.h.Andres Freund
All postgres internal usages are replaced, it's just libpq example usages that haven't been converted. External users of libpq can't generally rely on including postgres internal headers. Note that this includes replacing open-coded byte swapping of 64bit integers (using two 32 bit swaps) with a single 64bit swap. Where it looked applicable, I have removed netinet/in.h and arpa/inet.h usage, which previously provided the relevant functionality. It's perfectly possible that I missed other reasons for including those, the buildfarm will tell. Author: Andres Freund Discussion: https://postgr.es/m/20170927172019.gheidqy6xvlxb325@alap3.anarazel.de
2017-09-13Define LDAP_NO_ATTRS if necessary.Peter Eisentraut
Commit 83aaac41c66959a3ebaec7daadc4885b5f98f561 introduced the use of LDAP_NO_ATTRS to avoid requesting a dummy attribute when doing search+bind LDAP authentication. It turns out that not all LDAP implementations define that macro, but its value is fixed by the protocol so we can define it ourselves if it's missing. Author: Thomas Munro Reported-By: Ashutosh Sharma Discussion: https://postgr.es/m/CAE9k0Pm6FKCfPCiAr26-L_SMGOA7dT_k0%2B3pEbB8%2B-oT39xRpw%40mail.gmail.com
2017-09-12Allow custom search filters to be configured for LDAP authPeter Eisentraut
Before, only filters of the form "(<ldapsearchattribute>=<user>)" could be used to search an LDAP server. Introduce ldapsearchfilter so that more general filters can be configured using patterns, like "(|(uid=$username)(mail=$username))" and "(&(uid=$username) (objectClass=posixAccount))". Also allow search filters to be included in an LDAP URL. Author: Thomas Munro Reviewed-By: Peter Eisentraut, Mark Cave-Ayland, Magnus Hagander Discussion: https://postgr.es/m/CAEepm=0XTkYvMci0WRubZcf_1am8=gP=7oJErpsUfRYcKF2gwg@mail.gmail.com
2017-08-07Don't allow logging in with empty password.Heikki Linnakangas
Some authentication methods allowed it, others did not. In the client-side, libpq does not even try to authenticate with an empty password, which makes using empty passwords hazardous: an administrator might think that an account with an empty password cannot be used to log in, because psql doesn't allow it, and not realize that a different client would in fact allow it. To clear that confusion and to be be consistent, disallow empty passwords in all authentication methods. All the authentication methods that used plaintext authentication over the wire, except for BSD authentication, already checked that the password received from the user was not empty. To avoid forgetting it in the future again, move the check to the recv_password_packet function. That only forbids using an empty password with plaintext authentication, however. MD5 and SCRAM need a different fix: * In stable branches, check that the MD5 hash stored for the user does not not correspond to an empty string. This adds some overhead to MD5 authentication, because the server needs to compute an extra MD5 hash, but it is not noticeable in practice. * In HEAD, modify CREATE and ALTER ROLE to clear the password if an empty string, or a password hash that corresponds to an empty string, is specified. The user-visible behavior is the same as in the stable branches, the user cannot log in, but it seems better to stop the empty password from entering the system in the first place. Secondly, it is fairly expensive to check that a SCRAM hash doesn't correspond to an empty string, because computing a SCRAM hash is much more expensive than an MD5 hash by design, so better avoid doing that on every authentication. We could clear the password on CREATE/ALTER ROLE also in stable branches, but we would still need to check at authentication time, because even if we prevent empty passwords from being stored in pg_authid, there might be existing ones there already. Reported by Jeroen van der Ham, Ben de Graaff and Jelte Fennema. Security: CVE-2017-7546
2017-06-21Phase 3 of pgindent updates.Tom Lane
Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21Phase 2 of pgindent updates.Tom Lane
Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21Initial pgindent run with pg_bsd_indent version 2.0.Tom Lane
The new indent version includes numerous fixes thanks to Piotr Stefaniak. The main changes visible in this commit are: * Nicer formatting of function-pointer declarations. * No longer unexpectedly removes spaces in expressions using casts, sizeof, or offsetof. * No longer wants to add a space in "struct structname *varname", as well as some similar cases for const- or volatile-qualified pointers. * Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely. * Fixes bug where comments following declarations were sometimes placed with no space separating them from the code. * Fixes some odd decisions for comments following case labels. * Fixes some cases where comments following code were indented to less than the expected column 33. On the less good side, it now tends to put more whitespace around typedef names that are not listed in typedefs.list. This might encourage us to put more effort into typedef name collection; it's not really a bug in indent itself. There are more changes coming after this round, having to do with comment indentation and alignment of lines appearing within parentheses. I wanted to limit the size of the diffs to something that could be reviewed without one's eyes completely glazing over, so it seemed better to split up the changes as much as practical. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-08Improve authentication error messages.Heikki Linnakangas
Most of the improvements were in the new SCRAM code: * In SCRAM protocol violation messages, use errdetail to provide the details. * If pg_backend_random() fails, throw an ERROR rather than just LOG. We shouldn't continue authentication if we can't generate a random nonce. * Use ereport() rather than elog() for the "invalid SCRAM verifier" messages. They shouldn't happen, if everything works, but it's not inconceivable that someone would have invalid scram verifiers in pg_authid, e.g. if a broken client application was used to generate the verifier. But this change applied to old code: * Use ERROR rather than COMMERROR for protocol violation errors. There's no reason to not tell the client what they did wrong. The client might be confused already, so that it cannot read and display the error correctly, but let's at least try. In the "invalid password packet size" case, we used to actually continue with authentication anyway, but that is now a hard error. Patch by Michael Paquier and me. Thanks to Daniel Varrazzo for spotting the typo in one of the messages that spurred the discussion and these larger changes. Discussion: https://www.postgresql.org/message-id/CA%2Bmi_8aZYLhuyQi1Jo0hO19opNZ2OEATEOM5fKApH7P6zTOZGg%40mail.gmail.com
2017-05-25Abort authentication if the client selected an invalid SASL mechanism.Heikki Linnakangas
Previously, the server would log an error, but then try to continue with SCRAM-SHA-256 anyway. Michael Paquier Discussion: https://www.postgresql.org/message-id/CAB7nPqR0G5aF2_kc_LH29knVqwvmBc66TF5DicvpGVdke68nKw@mail.gmail.com
2017-05-19Fix compilation with --with-bsd-auth.Heikki Linnakangas
Commit 8d3b9cce81 added extra arguments to the sendAuthRequest function, but neglected this caller inside #ifdef USE_BSD_AUTH. Per report from Pierre-Emmanuel André. Discussion: https://www.postgresql.org/message-id/20170519090336.whzmjzrsap6ktbgg@digipea.digitick.local